METHODS OF RESTRAINT AND COMMON OPERATIONS 185 



Knowles' casting harness is simple in construction, besides being 

 cheap, durable, and easy to apply (Fig. 58). It consists of a wide 

 web collar, from which ropes extend backward on each side to the 

 hind pasterns. The free ends of the ropes are used to tie the feet 



Fig. 58. — Knowles' casting harness. 



and legs after the animal is thrown. An improvised harness for 

 emergency use to answer the same purpose can be constructed on 

 this plan from a long rope. 



ANESTHETIZING 



Anesthetics are used to render a part or the whole of the body 

 insensible for the purpose of performing operations with greater 

 dispatch and more safety to both the operator and the patient. 

 Local anesthetics are employed when the part operated upon is 

 limited in area. General anesthetics produce a loss of conscious- 

 ness, sensation, and motion. The muscles relax and the patient 

 lies motionless when anesthesia is complete. It should be under- 

 stood that accidents and dangers attend general anesthesia of the 

 horse. Chloroform and ether are the chief anesthetics used. 

 Either of these may be given while the horse is standing, by means 

 of a "mask" or "inhaler" that slips over the muzzle and straps 

 around the face. More often the animal is thrown, one nostril is 

 plugged with cotton, and he is made to inhale the fumes of the 



